This paper analyzes the defects and reasons for using standard BP neural network algorithm in building quality prediction model of yarns and explores an improved BP neural network algorithm. By increasing the back-propagation error-feedback signals and applying sell-adaptive and adjusting learning rate, the research has reinforced the adjustment of network weights and prevented network entering saturated region too early. These methods can increase the convergent speed of network and improve system stability. The experiment has proved that the forecast result is of high accuracy which comes from the improved BP neural network algorithm, and the design of quality prediction model is reasonable.